resetting $number count before entering while loop (in case of invalid cached number)

git-svn-id: svn://svn.code.sf.net/p/fhem/code/trunk@2813 2b470e98-0d58-463d-a4d8-8e2adae1ed80

fhem/FHEM/73_PRESENCE.pm

@@ -478,6 +478,8 @@ PRESENCE_DoLocalFritzBoxScan($)
 
     my $net_device;
 
+    $number = 0;
+    
     while($number <= $max)
     {
 	$net_device=qx(/usr/bin/ctlmgr_ctl r landevice settings/landevice$number/name);